Hundreds of new fires have flared up in the Amazon in Brazil, data showed Monday, even as military aircraft dumped water over hard-hit areas and G7 nations pledged 20 million U.S. dollars to help combat the blazes.

Swathes of the remote region have been scorched by the worst fires in years. Smoke choked Port Velho and forced the closure of the airport for nearly two hours as fires raged in the northwestern state of Rondonia where firefighting efforts are concentrated.

Seen from above, the destruction in Rondonia is dramatic: walls of flames advancing across the expansive forest beneath enormous plumes of thick smoke.

Seventy firefighters and troops have been deployed in Rondonia. Two C-130 Hercules aircraft carrying thousands of liters of water on Sunday began dousing fires devouring chunks of the world's largest rainforest.

Leaders of the G7 wealthy nations, which comprises Britain, Canada, France, Germany, Italy, Japan and the United States on Monday pledged 20 million U.S. dollars of emergency aid to help battle wildfires in the Amazon rainforest, as well as a separate 12 million U.S. dollars from Britain and 11 million U.S. dollars from Canada. Ottawa has also offered to send water bomber planes to Brazil.

Earth Alliance, a new environmental foundation backed by Leonardo DiCaprio, has also pledged five million U.S. dollars in aid.

Personal relations between French President Emmanuel Macron and Brazil President Bolsonaro, already has been strained by the crisis in the Amazon, with Macron threatening to block a huge new trade deal between the EU and Latin America unless Bolsonaro takes serious steps to protect the fast-shrinking forest from logging and mining.

Bolsonaro lashed out within minutes of G7's financial pledge that Brazil was being treated like "a colony or no man's land," and denounced the creation of an international alliance to save the Amazon as an attack on his nation's sovereignty.

It was not clear if Brazil would accept the G7 offer amid growing international concern. However, Brazil's Environment Minister Ricardo Salles struck a different note, calling the aid "welcome." Earlier, Bolsonaro had accepted an offer of support from Israeli Prime Minister Benjamin Netanyahu.

Macron has made climate change a top agenda on the G7 summit, saying G7 would draw up an initiative for the Amazon that will be launched at next month's UN General Assembly in New York. The initiative includes a reforestation plan.

Chilean President Sebastián Piñera was invited to join the G7 summit, and said the G7 initiative would be implemented in two stages.

"Countries urgently need fire fighters and specialized water bombers. This will be the first step that will be implemented immediately. The second phase is to protect these forests, protect the biodiversity they contain and reforest this region of the world," he added.

NASA says Brazil has 85 percent more fires burning than this time last year, up to 80,626 nationwide as of Sunday night. And Brazil's National Institute for Space Research (INPE) also reported that the state of Rondonia has seen 6,436 fires burning so far this year.

Many of the fires sweeping through the Amazon are thought to have been started deliberately in Brazil, with environmentalists blaming speculators who burn vegetation to clear it in hopes of selling the land to farmers and ranchers.

Bolsonaro has said that fires are part of the usual annual burn, in the dry season, and he also suggested NGOs could be setting the fires to embarrass him.

But critics have noted the government's policy of encouraging deforestation has boosted both the land clearance that helps fires rage. Experts say increased land clearing during the months-long dry season to make way for crops or grazing has aggravated the recurring problem this year.

Facing increased isolation abroad for his stance on the unfolding environmental crisis, Bolsonaro also found himself under mounting pressure at home, with a poll on Monday showing that his government's approval rating sank to 29.4 percent in August. And he has changed his tone, vowing a "zero tolerance" approach to criminal activities in the Amazon and promising strong action to control the blazes.

The Amazon is the largest rainforest in the world, spanning a number of countries, but 60 percent of it falls within Brazil. And it is home to three million species of plants and animals, as well as one million indigenous people from up to 500 tribes. Known as the "lungs of the world," the Amazon slows down the pace of global warming by absorbing carbon dioxide and producing oxygen.

(With input from agencies)